The biocontrol capability of Candida guilliermondii (Cast) Langeroret Guerra against Rhizopus stolonifer (Ehrenb.ex Fr.) Vuill. postharvest rot of peach fruits was studied in vitro and in vivo under different storage temperatures. C. guilliermondii at 5.0×108 CFU (colony-forming unit)/mL of washed cells provided complete control of 5×104 spores /mL of R. stolonifer during storage at 25 ℃ for 4 d, 15 ℃ for 7 d and 3℃ for 30 d. Temperature had no significant effect on the biocontrol efficacy. Antagonist population increased 45.6, 34.4 and 33.1 times per site at 25℃, 15℃ and 3℃ for 3, 3 and 7 d，respectively, then the population stabilized for the remaining storage period. Cell-free culture filtrate of C. guilliermondii was not effective in preventing decay and resulted in even greater lesion diameter than those of sterile distilled water at 3 ℃.These results showed that competition for nutrient, not antibiotic production, plays a major role in the biocontrol capability of C. guilliermondii against rhizopus rot of peach fruits. As the interval between wounding and inoculation with the pathogen increased from 0 to 72 h, susceptibility of wounds to decay by R. stolonifer decreased from 100% of 0 h to 5% of 4 h and 0% of 24 h, then increased to 10% of 48 h and 40% of 72 h.
季也蒙假丝酵母对采后桃果实软腐病的抑制效果
范青 田世平* 徐勇 汪沂 姜爱丽
（中国科学院植物研究所，北京100093）
摘要：研究了季也蒙假丝酵母 (Candidaguilliermondii (Cast)LangeroretGuerra)在培养基上和不同贮藏温度下对桃果实软腐病菌 (Rhizopusstolonifer (Ehrenb .exFr.)Vuill.)的抑制效果。结果表明 ,季也蒙假丝酵母的浓度越大 ,抑制效果越好 ;当接种孢子浓度为 5× 10 4 个 /mL时 ,在 2 5℃、15℃和 3℃ 3种贮藏温度下 ,5× 10 8CFU (colony_formingu nit) /mL的酵母悬浮液完全能抑制桃果实软腐病的发生。酵母悬浮液浓度为 1× 10 8CFU/mL时 ,以 2 4h后接种病菌孢子的抑菌效果最佳。季也蒙假丝酵母能在果实伤口处迅速繁殖 ,在 2 5℃、15℃和 3℃下分别培养 3d、3d和 7d时 ,酵母数量可增加 45 .6、34.4、33.1倍 ,并对果实不产生任何伤害。该菌不产生抗菌素 ,其抑菌机理可能与营养竞争等有关。
关键词： 桃；采后生物防治；季也蒙假丝酵母；软腐病
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